Technical Field
The present disclosure relates generally to the field of drilling heads. More particularly, the present disclosure relates to a cast drill head. Specifically, the present disclosure relates to a cast drill head including replaceable teeth arranging in a convex pattern and a ledge to self-align the drill head to a helical body/blade on the rotary auger.
Background Information
Rotary augers are tools used in drilling holes, and often powered by a motor. The conventional rotary auger includes at least one helical blade that lifts substrate material such as rock, dirt, and gravel upwardly from downhole as the auger rotates about a longitudinal axis to drill downwardly. Some rotary augers include two helical blades that wind about a drive shaft in a double-helical manner and cooperate to removably lift substrate from the hole during drilling.
Drilling heads are usually attached to the bottom (i.e. the downhole cutting end) of the rotary auger. The drill heads must be aligned to the bottom edge of the helical blade to ensure a smooth lifting of substrate. The drill heads ordinarily require precision alignments to ensure smooth upward flow out of the hole.
The drill heads may include a plurality of teeth attached thereto in order to cut or break the soil/rock substrate. Most of the known drill heads are on a “fixed-flat” cutting surface, which refers to cutter bits bolted onto a flat metal plate. The flat metal plate is substantially horizontal when viewed from the side. The teeth cut through the substrate as the auger rotates and bores downward. Furthermore, the teeth wear down through the continued use and require replacement when showing excess wear.